1. Field of the Invention
The present disclosure pertains to systems and methods to determine and/or estimate the fraction of inhaled oxygen on a breath-by-breath basis during ventilation of a subject.
2. Description of the Related Art
Various systems for ventilating patients are known. The concept of dead space within a respiratory/ventilation system is known, in particular, within a subject interface and/or a subject interface appliance. It is known that exhaled air has an increased mole fraction of carbon dioxide and a reduced mole fraction of oxygen compared to inhaled air. Various systems for expelling exhaled carbon dioxide from a respiratory/ventilation system are known. It is known that prolonged exposure during respiration to elevated levels of carbon dioxide or reduced levels of oxygen within the flow of breathed gas is, at the least, uncomfortable for patients.